Air injection system removal

This is for all of you airhead owners who have removed the air injection system on your bikes.

I have been having problems with my bike idling and running rough at low speed. Timing OKAY, Valves OKAY, rebuilt carbs. Still not right.

Turns out when I put the plugs in the heads after removing the injector hoses, I either did not get them tight enough or I used the wrong lock tight.

The plug is leaking on one side.

Just a heads up. St.

Don’t think a loose plug will make much difference in how the bike runs.

This location is outside the exhaust valve and is essentially in the exhaust system.

In addition the three Airheads I owned and removed this system from all had the fitting in the head loose.

It will make an interesting noise when the plug is loose, which could be perceived as different running when it actually isn’t.

I’d use crush washers rather than expecting any sort of performance from thread sealant in this application. Since the usual plug is an Oilhead engine oil drain plug, I’d do 32nm.

lkchris said:

Don’t think a loose plug will make much difference in how the bike runs.

This location is outside the exhaust valve and is essentially in the exhaust system.

In addition the three Airheads I owned and removed this system from all had the fitting in the head loose.

It will make an interesting noise when the plug is loose, which could be perceived as different running when it actually isn’t.

I’d use crush washers rather than expecting any sort of performance from thread sealant in this application. Since the usual plug is an Oilhead engine oil drain plug, I’d do 32nm.

Click to expand...

Kent,

I think it would cause problems with a lean condition on one cylinder. The reason I say this is because the intake and exhaust valves overlap. If there is a passage to outside air via a leak at the Pulse-air port in the exhaust valve passage, it would affect the reflected low pressure wave that the exhaust pipe creates to lower the pressure at the exhaust valve to improve purging. That pressure at the exhaust port would be higher due to air arriving from the leak in the pulse-air port. This would reduce exhaust gas purging from the cylinder. That would affect combustion on one cylinder and that would make the engine rough.

Right on Brook

Brook, you are right on the money. St.